In certain computer network configurations, a particular network domain (e.g., an autonomous system, or “AS”) may be “multi-homed” to the computer network, such that multiple paths or exits are available to that network domain to reach destination address prefixes located in a remote network domain. For example, this multi-homing may be provided by interconnecting the particular network domain to a plurality of service providers (e.g., Internet Service Providers, “ISPs”), often in order to achieve redundancy in the event of a failure, and/or to provide a mechanism that may be used to load balance (e.g., distribute) traffic destined to a remote domain. For instance, where available, multiple paths may share the traffic (the “load”) in an effort to reduce network congestion at any one service provider.
Currently, the particular (local) network domain may load balance traffic across these service providers, or more generally, these “first-hop domains” (being the first-hop from the particular local domain to reach any other remote domain), based on various factors. Simple algorithms may merely load balance traffic across each possible first-hop domain, regardless of how reliable the first-hop domains may be (that is, regardless of how well the traffic is handled through the first-hop domains, e.g., lost packets, delayed packets, etc.). More complex algorithms are also available that may distribute traffic across the multiple exits based on performance measurements of particular traffic-classes. For example, through either passive monitoring or active probing for each traffic-class, traffic for each traffic-class may be routed/forwarded over a specific best performing path/exit to reach a particular destination address prefix in a remote domain.
These performance measurements, however, while being generally accurate in determining a best performing path per-traffic class and per-prefix, may be more information than necessary for certain networks. For example, certain networks may desire simple load balancing across multi-homed first-hop domains, as opposed to more complex performance-based routing to determine a particular path/exit for specific traffic-classes to specific destination address prefixes.